<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div {
            width: 100px;
            height: 100px;
            border: 1px solid red
        }

        #d1 {
            /*
            margin-left: 50px;
            margin-top: 50px;
            margin-bottom: 50px;

            margin-right: 50px;
             */

            /*margin: 50px;/*4个方向50个像素的外边距*/
            /*margin: 50px 100px;/*上下50,左右100*/
            margin: 10px 20px 30px 40px; /*上下左右*/
        }

        #d2 {
            /*上下相邻两个元素彼此添加外边距 取最大值*/
            margin-top: 50px;
        }

        #s1{
            /*行内元素上下外边距无效*/
            margin-bottom: 100px;
            margin-right: 50px;
        }
        #s2{
            /*左右相邻彼此添加外边距两者相加*/
            margin-left: 50px;
        }
    </style>
</head>
<body>
<span id="s1">span1</span><span id="s2">span2</span>
<div id="d1">div1</div>
<div id="d2">div2</div>
</body>
</html>